Where does “Թորոսյան” come from?

Թորոսյան (Armenian) comes from Armenian Թորոս, from Old Armenian Թորոս, from Old Armenian Թէոդորոս, from Ancient Greek Θεόδωρος, from Ancient Greek δῶρον, from Proto-Hellenic dṓron, from Proto-Indo-European déh₃rom, from Proto-Indo-European deh₃- — to give.

Թորոսյան (Armenian): Torosyan, Torosian, Torossian